SetsulWell then you are fucked.
Anything faster than a 660 Ti but not as fast as a 1070 is sold out or massively overpriced.
Anything as fast or faster than a 1070 you can't afford.
I mean the only thing you can afford that's faster (not just 30% I mean) than your 660 Ti would be one of the 1060s that is still in stock.
But name a "game from 2016 onward" and I'll tell you that you won't get 60 fps on high at 1440p.
E.g. Witcher 3 (2015)
https://tpucdn.com/reviews/NVIDIA/GeForce_GTX_1060/images/witcher3_2560_1440.png
see i wouldnt mind a 1060, since i have no issue lowering the graphics, just as long as lets say the 1060 is a worty upgrade from the 660ti. i was also looking at the 470, 560 and 570 but i have no idea how they perform